Bromine → N-(8-Bromobenzo[1,4]dioxan-5-yl)-acetamide

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of N-(2,3-dihydrobenzo[b][1,4]dioxin-5-yl)acetamide (5.5 g, 28.5 mmol) in chloroform (20 mL) cooled at −20° C. was slowly added a solution of bromine (1.6 mL, 30 mmol) in chloroform (5 mL) so that the reaction temperature was maintained below −10° C. The reaction was stirred at 0° C. for 10 minutes, and then quenched immediately with water. The mixture was extracted with dichloromethane; the combined extracts were washed with saturated sodium bicarbonate and brine, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was subjected to silica gel chromatography (dichloromethane) to afford the product N-(8-bromo-2,3-dihydrobenzo[b][1,4]dioxin-5-yl)acetamide (5 g, yield 64%). 1H NMR (400 MHz, CDCl3) δ ppm 9.23 (s, 1H), 7.46-7.48 (d, 1H, J=8.8 Hz), 7.04-7.06 (d, 1H, J=9.2 Hz), 4.32-4.40 (m, 4H), 2.07 (s, 3H).

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